Reflector mounting



Feb. 19, 1935. I R, P, MAY 1,991,861

REFLECTOR MOUNTING Filed May 2, 1951 l Fig.3.

j 1 my 1 1 1 I i 1114 1/ g i 1 18 1 i i 6 Fig.4.

2 INVENTOR RusseLLF? Mag, B19

8 UAN,

HIS ATTORNE Q Patented Feb. 19, 1935 PATENT OFFICE 1,991,861 REFLECTORMOUNTING Russell P. May, Haddonfield, N. J., assignor, by mesneassignments, to Radio Corporation of America, New York, Delaware N. Y.,a corporation of Application May 2, 1931, Serial No. 534,542

3 Claims.

My invention relates to moving picture apparatus and, more particularly,to a mounting for the reflector utilized in connection with theprojector lamp.

In apparatus of this type, light from a suitable source is concentratedonto a moving film whereby images appearing on the film are projectedonto a distant screen through a suitable optical system. Where the lightsource employed is in lo the form of an incandescent lamp, it isdesirable,

in order to increase the light efficiency, to employ a suitablereflector in connection with the lamp, so that not only direct rays, butalso reflected rays will be projected onto the screen.

Incandescent lamps used for this purpose are usually provided withfilaments of two or three coils, and it has been found that withlamps'of this kind, although the light eflicieney is increased by theuse of a reflector, it is, nevertheless, ordinarily diflicult to obtainmaximum light efliciency. This is due to the fact that the rays of lightemanating directly from the lamp form one image of the lamp filamentthrough the condenser lenses,'while the light rays reflected by thereflector form a second image which, ordinarily, is superposed eitherpartially or entirely on the first image. The result is that light islost and streaks or spots of varying light are formed on the screen, auniform distribution of the light becoming extremely diflicult, if notaltogether impossible.

The principal object of my invention is to obviate this difficulty, andI accomplish this by providing a focus adjusting means in connectionwith the reflector for focusing to control the intensity of theprojected light, and a light distribution adjusting means whereby theprojected light may be uniformly distributed over the screen, thusrelieving eye-strain and permitting maximum enjoyment of the viewedpictures.

Another object of my invention is to provide an improved reflectormounting wherein the light distribution adjusting means may act as aguide for thelfocus adjusting means.

Still another object of my invention is to provide an improved reflectormounting wherein the adjusting mechanism will simultaneously lockthereflector in adjusted position once it has been adjusted. I

A further object of my invention is to provide an improved reflectormounting wherein the reflector may be adjusted externa Iy of the lamphousing even during operation, i desired, making it unnecessary todismantle any of the parts once they are set up for use.

Still a further object of my invention is to provide an improvedreflector mounting wherein, once the adjustments have been made, readyaccess to the adjusting means will be prevented so that they may not betampered with or disturbed without removing a portion of the lamphousing.

Another object of my invention is to provide an improved reflectormounting of the type set forth which will be rugged, durable inconstruction and eflicient in use, as well as being compact and. wellsuited to the requirements of commercial manufacture.

The novel features of my invention are set forth with particularity inthe appended claims, the invention itself, however, both as to itsorganization and its method of operation, together with additionalobjects and advantages thereof, being best understood from the followingdescription of a specific embodiment, when taken in connection with theaccompanying drawing in which Figure 1 is a side elevation, partly insection, of a lamp housing provided with reflector adjusting meansaccording to my invention;

Fig. 2 is an exploded perspective view of the adjusting means andreflector;

Fig. 3 is a diagrammatic view illustrating how the light may be evenlyand uniformly distributed by means of my improved adjusting means, and

Fig. 4 is a detailed section of a portion of the adjusting mechanism.

Referring to the drawing wherein similar reference characters indicatecorresponding parts throughout, my improved reflector mounting comprisesa support or boss 1 formed on a lamp housing 2 in the base 3 of which isprovided a socket for the reception of an incandescent lamp 4. The lamp4 is provided with a filament 5 which may be of any suitable number ofcoils, only two coils, 5a and 5b, being shown in the drawing for thesake of simplicity. Light rays leaving the lamp 4 may pass directlythrough condensers 6 onto an intermittently moving film (not shown)whereby images appearing on the film are successively projected onto adistant screen (not shown) in a manner well known to those skilled inthe art.

In order to increase the amount of light concentrated upon the film' andeventually projected onto the screen, a suitable reflector '7 may beprovided, the reflector 7 being mounted in a frame or casingia andpositioned diametrically opposite to the condensers 6. Light raysleaving the filament 5 and reaching the reflector 7 are then reflectedback through the condensers 6, thus augmenting the rays passed directlythrough the condensers 6 by the filament 5.

The support or boss 1 is provided with a recess 9 and a centrallydisposed bore 11, while the reflector frame or casing 8 is provided witha boss 12 which is internally threaded to receive a screw 14 extendingthrough the bore 11, whereby the casing 8 is substantially aligned withthe boss 1. It will be noted that the diameter of the bore 11 is greaterthan that of the threads of the screw 14 for a purpose indicatedhereinafter. By manipulating the screw 14 within the bore 11, thereflector 7 will be moved along its optical axis for the purpose offocusing, the screw 14 being limited in its axial movement by the bosses1 and 12 at one end and by its own head 15, in engagement with ashoulder 16 of a counterbore 17, at the other end. By reason of the bore11 being larger than the cross sectional dimension of the screw 14, itwill be obvious that the screw 14 may also be moved transversely of thebore 11 within the limits thereof.

The boss 1 is also provided with a plurality of screw-threaded openings18 circumferentially disposed thereon about and radially spaced from thebore 11. In the drawing, three such openings are shown spaced from eachother. The casing 8 is provided with a similar number of openings 19aligned with the openings 18. Threaded in each opening 18 is a screw 20having a reduced or rounded end portion 21 bearing against the back ofthe casing 8 and terminating in a still further reduced extension 22which fits into the correspondingly aligned opening 19 of the casing 8.The openings 19 are of slightly greater diameter than that of theextensions 22 for a purpose to be hereinafter described.

By reference to Figures 1 and 3, the operation of my improved mountingand adjusting means will now be made clear. The light rays emitted bythe coils 5a and 5b of the filament 5 directly toward the condensers 6are projected onto a distant plane 28 to form an inverted image 25a,25b. Light rays emitted by the coils 5a and 5b toward the reflector 7are reflected thereby and pass through the condensers 6 to formanupright image 35a, 35b. In order to obtain the brightest image on thescreen, the screw 14 may be manipulated to adjust the reflector 7 alongits optical axis until an image is focused on the plane 28, the casing 8moving along the extensions 22 which act as guides therefor. However,this adjustment alone does not prevent the images 25a, 25b and 35a, 35bfrom being superposed, either partially or entirely over one another,and in such case, light loss results and there appear streaks of lighton the screen during picture projection, the light being non-uniformlydistributed thereon and being tiresome to the eyes of the observer.

In order to obviate this condition, I have provided the adjusting screws20. These screws may be manipulated individually to tilt the reflector7,

by reason of the reduced ends 21 hearing on the casing 8, thus changingthe direction of the optical axis of the reflector 7 until the images25a, 25b and 35a, 35b are staggered and evenly spaced with respect toeach other, as clearly shown in Figure 3. This results in increasedlight efliciency, and the screen becomes uniformly illumi nated byvirtue of the even and uniform distribution of light thereover.

When the reflector has been soadjusted, it is simultaneously locked inadjusted position by the screw head 15 bearing against the shoulder 16and the reduced ends 21 of the screws 20 bearing against the rear of thecasing 8, the openings 19 and. the bore 11 permitting free and easyadjustment, since they are respectively larger than the extension 22 andthe screw 14. This adjustment will, of course, be maintained untildisturbed. In order to prevent ready access to the screws 14 and 20 andthus, possibly, accidentally disturbing this adjustment, a cover plate40 may be inserted into the recess 9 and held therein in any suitablemanner, as by screws 41.

It will thus be seen that I have provided a reflector mounting whereinthe adjusting means may be easily and quickly operated for focusing anduniformly distributing on a screen the light emitted by the lamp of aprojector in such a manner as to produce maximum results and optimumenjoyment of the viewed pictures. It will further be seen that I haveprovided a reflector mounting wherein dismantling of any of the parts isunnecessary when it is desired to adjust the position of the reflector,the reflector being locked in adjusted position automatically once ithas been adjusted, and to which ready access is prevented, therebyeliminating accidental displacement or disturbance of adjusting members.

Although I have shown and described a' cer- U tain specific embodimentof my invention, I am fully aware that many modifications thereof arepossible. Furthermore, although I have shown my invention as applied toa reflector mounting utilized in connection with the projector lamp ofmoving picture apparatus, it will be obvious that my improved reflectormounting may be employed in many other types of apparatus. My invention,therefore, is not to be restricted except insofar as is necessitated bythe prior art and by the spirit of the appended claims.

I claim as my invention:

1. The combination with a reflector and a casing therefor of a mountingfor said casing comprising a support, means loosely fitted in saidsupport and engaging said casing for adjusting said reflector lineally,and means threaded in said support and loosely engaging said casing fortilting said casingand reflector.

2. The combination with a reflector and casing therefor of a mountingfor said casing comprising a support, a screw loosely fitted in saidsupport and threadedly engaging said casing for adjusting said casingand reflector lineally relative to said support, a plurality of screwsthreaded in said support about said screw and arranged to engage saidcasing adjacent the periphery thereof for tilting said casing andreflector relative to said support, and means on said support forpreventing ready disturbance of the adjustment of said screws.

3. The combination with a reflector and casing therefor having aplurality of apertures circumferentially disposed thereon of a mountingcomprising a support, a screw loosely fitted in said support andthreadedly engaging said casing for adjusting said casing and reflectorlineally relative to said support, and a plurality of screws threaded insaid support about said loosely fitted screw and having reduced endsfitted within said apertures to form guide means for said casing in itslineal movement relative to said support.

RUSSELL P. MAY.

